Differential volatile organic compounds in royal jelly associated with different nectar plants

The aim of this work was to distinguish volatile organic compound（VOC） profiles of royal jelly（RJ） from different nectar plants. Headspace solid-phase microextraction（HS-SPME） was used to extract VOCs from raw RJ harvested from 10 nectar plants in flowering seasons. Qualitative and semi-quantitative analysis of VOCs extracts were performed by gas chromatography-mass spectrometry（GC-MS）. Results showed that VOC profiles of RJ from the samples were rich in acid, ester and aldehyde compound classes, however, contents of them were differential, exemplified by the data from acetic acid, benzoic acid methyl ester, hexanoic acid and octanoic acid. As a conclusion, these four VOCs can be used for distinguishing RJ harvested in the seasons of different nectar plants.

Olfactory Response of Trichogramma ostriniae (Hymenoptera: Trichogrammatidae) to Volatiles Emitted by Mungbean Plants

Intercropping maize with the prostrate variety of mungbean, Vigna radiata （L.） Wilczek which grows flat along the ground can increase parasitism of the eggs of the Asian corn borer, Ostrinia furnacalis （Guenée）, a crucial insect pest of maize in China, by Trichogramma ostriniae Pang Chen. This study investigated the behavioural responses of T. ostriniae to plant volatiles emitted from whole plants, leaves, and flowers of prostrate and erect varieties of mungbean in a 4-armed olfactometer. Female parasitiods were significantly attracted to the odours from some varieties of prostrate mungbean when the visit duration and the number of visits were considered, but were not attracted to the odours from any erect varieties. The attractive odours were shown to emanate from the leaves, rather than from the flowers of prostrate mungbean plants. These results have implications for the augmentation of Trichogramma parasitoids in bio-control of O. furnacalis and other crop pests.

Electrophysiological responses of Plutella xylostella to 9 different plant volatiles

Plutella xylostella is the main pest of cruciferae plants in the worldwide fields.The volatiles released from host plants serve vital roles in host-finding and oviposition behavior.Electroantennograms were recorded from male and female Plutella xylostella to 9 different plant volatiles(cabbage Brassica oleracea L.var.capitata,baby bokchoi Brassica chinensis L.,broccoli Brassica oleracea L.var.botrytis L.,Chinese cabbage Brassica pekinensis Rupr.,Radish Raphanus sativus L.,towel gourd Luffa Cylindrica Roem.,eggplant Solanum melongena L.,tomato Solanum lycopersicum,pepper Capsicum annuum L.) in healthy/injured status.The statistic analysis show there is a significant difference of EAG relative values between cruciferae and non-cruciferae volatiles.The EAG relative values of injured plant volatiles to both male and female changed a lot during the tests.Multiple-ANOVA analysis represents cross factors(sex,host-plant,plant status) showed a great interactive impacts to the EAG-RV.

Plant Senescence: The Role of Volatile Terpene Compounds (VTCs)

Senescence is a natural, energy-dependent, physiological, developmental and an ecological process that is controlled by the plant’s own genetic program, allowing maximum recovery of nutrients from older organs for the survival of the plant, as such;it is classified as essential component of the growth and development of plants. In some cases, under one or many environmental stresses, senescence is triggered in plants. Despite many studies in the area, less consideration has been given to plant secondary metabolites, especially the role of VTCs on plant senescence. This review seeks to capture the biosynthesis and signal transduction of VTCs, the physiology of VTCs in plant development and how that is linked to some phytohormones to induce senescence. Much progress has been made in the elucidation of metabolic pathways leading to the biosynthesis of VTCs. In addition to the classical cytosolic mevalonic acid (MVA) pathway from acetyl-CoA, the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway, originating from glyceraldehyde-3-phosphate (GAP) and pyruvate, leads to the biosynthesis of isoprenoid precursors, isopentenyl diphosphate and dimethyl allyl diphosphate. VTCs synthesis and emission are believed to be tightly regulated by photosynthetic carbon supply into MEP pathway. Thus, under abiotic stresses such as drought, high salinity, high and low temperature, and low CO2 that directly affect stomatal conductance and ultimately biochemical limitation to photosynthesis, there has been observed induction of VTC synthesis and emissions, reflecting the elicitation of MEP pathway. This reveals the possibility of important function(s) of VTCs in plant defense against stress by mobilizing resources from components of plants and therefore, senescence. Our current understanding of the relationship between environmental responses and senescence mostly comes from the study of senescence response to phytohormones such as abscisic acid, jasmonic acid, ethylene and salicylic acid, which are extensively involved in response to various abiotic and biotic stresses. These stresses affect synthesis and/or signaling pathways of phytohormones to eventually trigger expression of stress-responsive genes, which in turn appears to affect leaf senescence. Comparison of plant response to stresses in relation to patterns of VTCs and phytohormones biosynthesis indicates a considerable crosstalk between these metabolic processes and their signal to plant senescence.

Attraction of bruchid beetles Callosobruchus chinensis (L.) (Coleoptera: Bruchidae) to host plant volatiles

Host-plant volatiles play an important role as cues for herbivores in search of resources, mates and oviposition sites in complex environments. Plant volatile-based attractants can be developed for pest monitoring and control. Previously, we indicated that mated female adults of Callosobruchus chinensis showed choice preference behavior toward 2-hexenal and benzaldehyde. Our objective here was to investigate the synergistic effect of host-derived attractive volatiles in attracting C. chinensis under laboratory and field conditions in Shanxi Province, China. We hypothesized that the ratio and concentration of volatiles derived from Vigna radiata play critical roles for C. chinensis in locating this host. Therefore, we collected and identified the volatiles of mungbean by using headspace collection and GC-MS. The effectiveness of different ratios and concentrations of two compounds (2-hexenal and benzaldehyde) that elicit C. chinensis searching behavior were examined in Y-tube olfactometer assays. The combination of 300 μg μL^–1 2-hexenal and 180 μg μL^–1 benzaldehyde loadings exhibited a synergistic effect on attracting C. chinensis (82.35%). Compared to control traps, the adults were significantly attracted to traps baited with blends, and more attraction to females than males was found for blend traps in the field experiments. Our results suggest that blends of this specific concentration and ratio of benzaldehyde and 2-hexenal can be used in traps as attractants for C. chinensis monitoring and control in the field.

Electrophysiological and Behavioral Responses of Adult Anoplophom glabripennis (Motschulsky) to Volatile Components of Host-Plant

Electrophysiological and behavioral responses of adult A. glabripennis (Motsch.) to volatiles from ashleaf maple (Acer negundo L.) were investigated to identify semiochemicals involved in host location. Measurable electroantennogram (BAG) responses were elicited to all compounds tested, the most effective antennal stimulants were trans-2-hexen-1-al,decyl aldehyde and trans-2-hexenl-ol.These profiles were similar between males and females. In Y-tube olfactometer bioassays, above three compounds with certain concentration, trans-2-hexen-l-al (1%), trans-2-hexen-l-ol (1%) and decyl aldehyde (10%), were significantly attractive to the adults in laboratory. The results show that either BAG or olfactory responding to a particular volatile compound are markedly influenced by the concentration.

Screening of Slow Release Solvents for Plant Volatiles

[Objective] The paper was to study the slow release effects of eight common kinds of slow release solvents on n-hexane, and to provide a reference for the construction of slow release system of attractants or repellents synthesized by plant volatiles. [Method] The effect of slow release solvents on volatile quantity and release rate of n-hexane was compared by weight loss method. [Result] Under indoor natural conditions [(22±2) ℃,RH 50%±10%], the slow release effect of lubricating oil on n-hexane was the best, followed by liquid paraffin. The best ratio of slow release solvent(lubricating oil and liquid paraffin) and n-hexane was 5∶1 and the best mixing time was 3 h, which improved the slow release effects of n-hexane by6.3 and 4.7 times, and prolonged the half-life of n-hexane by 1.3 and 1.0 times, respectively. Slow release solvents mainly affected the post-half-life period of n-hexane, and the release rates of n-hexane mixed with lubricating oil and liquid paraffin were decreased by 10.4 and 7.7 times, respec-tively. During the half-life period, the release rates of n-hexane were decreased by 1.3 and 1.0 times, respectively. [Conclusion] Two kinds of slow release solvents with good slow release effect on volatile n-hexane are screened out, and the proportion and mixing time of slow release solvent and volatile are determined, which will provide technical support for the construction of plant volatile slow release system.

Volatiles from Sophora japonica flowers attract Harmonia axyridis adults(Coleoptera: Coccinellidae)

The multicolored Asian lady beetle, Harmonia axyridis(Coleoptera: Coccinellidae), is a common generalist predator in China and is occasionally found gathering on the Chinese pagoda tree, Sophora japonica, in summer. In a field investigation, we found that H. axyridis adults preferred S. japonica during its flowering period even though their optimal prey(aphid) is absent at this time. In addition, male and female adults were attracted to S. japonica flowers to a similar extent in a Y-tube olfactometer assay. Using coupled gas chromatography-electroantennogram detection(GC-EAD), we identified a flower odor component(nonanal) that elicited a significant electrophysiological response in H. axyridis. Electroantennogram(EAG) dose-dependent responses revealed that the amplitude of the adult beetle's EAG response increased with increasing concentration of nonanal, peaking at 10 mg mL^(–1). In Y-tube olfactometer behavioral tests, H. axyridis adults preferred a 10 mg mL^(–1) nonanal source over a 100 mg mL^(–1) diluent. Under field conditions, the adults were significantly attracted to both concentrations(10 and 100 mg mL^(–1)), and high concentrations generally had greater attraction. All these results suggest that nonanal, a volatile compound of S. japonica flowers, greatly attracts H. axyridis adults. This study provides a basis for the development of synthetic attractants of H. axyridis, with the potential to promote biocontrol services of this generalist predator in the native area(e.g., China) and to suppress its population by mass trapping in its invasive areas.

Plant-Derived Enzymes Producing Chiral Aroma Compounds and Potential Application

Aroma(volatile)compounds play important ecological functions in plants,and also contribute to the quality of plant-derived foods.Moreover,chiral aroma compounds affect their functions in plants and lead to different flavor quality properties.Formations of chiral aroma compounds are due to the presence of enzymes producing these compounds in plants,which are generally involved in the final biosynthetic step of the aroma compounds.Here,we review recent progress in research on the plant-derived enzymes producing chiral aroma compounds,and their changes in response to environmental factors.The chiral aroma enzymes that have been reported produce(R)-linalool,(S)-linalool,(R)-limonene,and(S)-limonene,etc.,and these enzymes are found in various plant species.We also discuss the origins of enantioselectivity in the plant-derived enzymes producing chiral aroma compounds and summarize the potential use of plants containing enzymes producing chiral aroma compounds for producing chiral flavors/fragrances.

3种寄主挥发物中引起旋幽夜蛾嗅觉反应的活性组分分析

为探究植物挥发物中引起旋幽夜蛾嗅觉电生理反应的活性组分,本研究采用动态顶空吸附法收集藜、甜菜和棉花植株的挥发物,利用气相色谱触角电位联用仪(GC-EAD)和气相色谱质谱联用仪(GC-MS)定性鉴定寄主挥发物中引起旋幽夜蛾嗅觉反应的活性组分。结果表明,藜挥发物中有6种活性组分,甜菜和棉花挥发物中各有5种,其中乙酸叶醇酯、1,2-二乙苯、对二乙苯、壬醛、二乙二醇丁醚为3种植物共有的挥发物组分,异佛尔酮仅在藜挥发物中发现。触角电位(EAG)测定结果显示,以上6种组分都能引起旋幽夜蛾雌雄成虫的EAG反应,且随浓度增加EAG相对反应值增大。雌雄成虫对壬醛和异佛尔酮的EAG反应最强烈,其次是乙酸叶醇酯和1,2-二乙苯。在相同浓度条件下,雌雄成虫对同种化合物的EAG反应无性别特异性。本研究为探明旋幽夜蛾定位寄主机制及开发行为调控产品提供基础。

Effects of herbivore-induced rice volatiles on the host selection behavior of brown planthopper,Nilaparvata lugens

It has been suggested that herbivore would react to volatiles produced by herbivore infested plant due to potential change, either positive or negative, in the acceptability of the host plant. This hypothesis was tested for the brown planthopper (BPH) in the laboratory. Sixteen components of the headspace volatiles from rice seedlings with different treatments were collected with SPME and Tenax-TA trap and analyzed with GC and GC-MS. Significant differences in volatile emissions were observed for rice plants with different treatments. Undamaged control plants, mechanically damaged plants and the plants infested by BPH for 1 or 2 d emitted much lower amounts of volatiles compared to the plants infested by BPH for 3 or 5 d. The plants infested by BPH for 3 or 5 d emitted several volatiles that were not detected in undamaged control plants, mechanically damaged plants or the plants infested by BPH for 1 or 2 d. Spodoptera litura infested plants released much higher amounts of volatiles than those in all

松墨天牛对小蠹危害后马尾松挥发物的气相色谱-触角电位联用技术反应

为探究松树材小蠹(Xyleborus festivus Eichhoff)与松墨天牛(Monochamus alternatus Hope)之间协同危害马尾松(Pinus massoniana Lamb)的机制,防控松墨天牛对松材线虫病的传播,采用动态顶空吸附的方法,收集了受松材线虫感染和松树材小蠹蛀干危害后的马尾松侧枝、以及其生长端上的1年生松梢的挥发物,利用气相色谱-质谱联用技术(GC-MS)和气相色谱-触角电位联用技术(GC-EAD),鉴定和筛选了能引起未交配松墨天牛在营养补充时期成虫触角电位反应的组分。结果表明:在鉴定出的24种化合物中有8种为活性物质,分别是α-蒎烯、莰烯、左旋-β-蒎烯、右旋萜二烯、长叶烯、假柠檬烯、萜品油烯和β-石竹烯。结合文献分析,推测α-蒎烯、左旋-β-蒎烯、莰烯、右旋萜二烯和β-石竹烯在吸引天牛取食方面有重要作用,并且假柠檬烯与右旋萜二烯两组分可能与小蠹危害有关。后续将通过室内行为试验进一步筛选能吸引未交配松墨天牛成虫的物质。

蜜蜂气味结合蛋白与外源性化合物互作机制研究进展

嗅觉是蜜蜂赖以生存和繁殖的主要感官方式,可为蜜蜂外出觅食、躲避天敌、交配等行为提供重要信息,而气味结合蛋白(odorant-binding proteins,OBPs)在其嗅觉感知中发挥着关键作用。探究外界环境中各种化学物质与蜜蜂OBPs之间的相互作用,对于揭示蜜蜂OBPs对不同外源性化合物的结合特性和结合机制具有重要意义。外源性化合物主要包括化学信息物质(信息素和蜜源开花植物挥发物)以及杀虫剂等农用化学品。一方面,化学信息物质与蜜蜂OBPs结合,在维持蜂群稳定、繁殖、觅食、授粉等生理功能中发挥着重要作用;另一方面,杀虫剂与蜜蜂OBPs结合则可能危害蜜蜂嗅觉系统,影响或干扰蜜蜂对环境气味分子的识别。本文综述了蜜蜂OBPs的种类、功能及其与外源性化合物互作机制的研究进展,以期为深入探究蜜蜂OBPs的生理功能、保护蜜蜂免受杀虫剂等化学物质的危害提供参考。

亚洲柑橘木虱对两种寄主植物嫩芽及其挥发物的行为反应

亚洲柑橘木虱Diaphorina citri Kuwayama是柑橘嫩梢期的重要害虫,也是柑橘黄龙病的传播媒介。本文采用顶空固相微萃取和气质联用技术(GC-MS)测定了九里香Murraya exotica L.、砂糖橘Citrus reticulate cv. Shatangju不同发育状态嫩芽的挥发性成分,并利用四臂嗅觉仪测定了亚洲柑橘木虱成虫对九里香和砂糖橘嫩芽中的4种共有挥发性成分葎草烯、正己醛、石竹烯、反式-2-己烯醛的趋性反应,从行为学反应和化学成分等方面深入研究了亚洲柑橘木虱和寄主植物挥发物的关系,以期探究植物源气味在亚洲柑橘木虱寄主选择中的作用。结果表明:(1)砂糖橘未展开嫩芽、半展开嫩芽分别含有36种、41种挥发性物质,全展开嫩芽和新叶分别含有32种和37种挥发性物质,九里香未展开嫩芽和展开嫩芽分别含有20种和14种挥发性物质;(2)两种植物不同发育状态嫩芽的共有挥发物有8种,分别是葎草烯、正己醛、石竹烯、反式-2-己烯醛、[S-(E,E)]-1-乙基-5-亚甲基-8-(1-甲基乙基)-1,6-环癸二烯、α-荜澄茄油烯、γ-芹子烯和δ-杜松烯;(3)亚洲柑橘木虱成虫对10μL/mL石竹烯、100μL/mL反式-2-己烯醛以及1μL/mL葎草烯有明显的正趋性,研究结果可为亚洲柑橘木虱引诱剂的开发提供依据。

新型驱蚊虫成分及制剂的研究概况

蚊虫可传播多种疾病,且发病率和病死率较高,严重威胁人类健康。目前以化学合成药为主的驱蚊虫剂在使用中面临诸多严重问题,如对人体产生副作用、造成环境污染、蚊虫种群产生耐药性。因此研究开发新型驱蚊虫活性成分受到全球广泛关注。本文主要综述了石墨烯衍生物、环境友好型植物精油以及部分合成化学品在驱蚊虫方面的研究概况。

生长期施用GA_(4+7)对黄冠梨贮藏过程中挥发性有机化合物的变化影响

为了研究生长期赤霉素4+7(GA_(4+7))的施用对梨果贮藏期香气品质的影响,采用顶空固相微萃取(HS-SPME)结合全二维气相色谱/飞行时间质谱(GC×GC/TOFMS)进行分析。经分析发现在对照组和GA_(4+7)处理组中均检测到酯、烯烃、醇、醛、酮、烷烃、芳烃和硫化物8大类挥发性物质,其中,酯类、醇类、醛类和烯烃是主要的挥发性香气成分。在贮藏当天,GA_(4+7)处理组的挥发性物质总质量浓度和数量最高,是对照组的1.72倍,然而在贮藏50 d后,GA_(4+7)处理组中挥发性物质的质量浓度和数量便迅速下降。此外,主成分分析和热图分析表明,贮藏过程中GA_(4+7)处理组与对照组之间的香气变化有显著差异。进一步的香韵分析表明,GA_(4+7)处理可以增加果实贮藏当天的果味香型质量分数占比,但会降低贮藏期梨果的果味香型。上述研究全面阐明了在生长期施用GA_(4+7)对梨果实贮藏期间挥发性成分的影响,为梨贮藏期的确定和生产管理提供了重要的理论支持。

植物根际促生菌:作用机制与未来

能够促进植物生长的植物根际细菌统称为植物根际促生菌(PGPR)。PGPR的应用可以减少农药化肥的使用,有助于农业可持续性发展。过去二十多年中,围绕PGPR功能与作用机理相关的理论与应用研究取得了显著进展。本文旨在总结PGPR的促生与生防机制,重点探讨PGPR在参与植物营养元素的改善与摄取、产生植物激素、分泌信号小分子、合成挥发性有机化合物促进植物生长以及合成抗生素类物质拮抗植物病原菌五个方面的生物学功能,并探讨了PGPR在基础与应用两方面的后续研究方向,以期为未来PGPR相关研究提供理论参考。

不同负荷梯度对污水厂活性污泥的产酸性能分析

活性污泥发酵产酸有利于实现污泥资源化利用。文中以污水厂活性污泥为研究对象,在污水厂现场采用半连续碱性发酵方法,探究了先低梯度再高梯度长周期提负荷过程中污泥的产酸性能。结果表明:低梯度提负荷运行阶段,第112 d污泥的酸化率达到最大值,且乙酸占比为71.67%,游离氨(FA)质量浓度为(208±39)mg/L,低于250 mg/L,对微生物无抑制性。在高梯度提负荷阶段,第192 d污泥的水解率提高至41%,丁酸与戊酸的占比增加,FA质量浓度逐渐升高至450 mg/L时产酸性能下降。低梯度的优势菌Guggenheimella(24.88%)演变为高梯度的unclassified_Clostridiales(37.08%)。此外,当负荷为3250 mg TSS/(L·d)时,挥发性脂肪酸(VFAs)达到最大值(3339 mg COD_(Cr)/L)。经过50 d的稳定运行,污泥的产酸率为(606±30)mg COD_(Cr)/(g VSS)。合适的负荷梯度有助于污泥中有机物在碱性条件下(pH值=10.0±0.05)长期稳定连续生成VFAs。

健康和物理损伤条件下椰树叶柄挥发物组分比较分析

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走航技术在石化企业VOCs排放监测中的应用

石化企业是典型的挥发性有机化合物(VOCs)排放源,排放特征总体表现为源头多、分布广、波动大、无组织排放占比高,因而监测和管控难度较大。采用搭载快速响应光谱分析仪的监测车在石化企业厂区走航监测烷烃、烯烃及苯系物等代表性VOCs组分的浓度及分布,发现烷烃污染在全厂区域均有分布,其中6个生产装置及10个储罐区域存在持续性烷烃排放,烯烃与苯系物污染分布只限于少数区域。走航监测能显著提升监测的时效性和空间覆盖度,可明确石化企业不同生产装置和储罐区域的VOCs排放特征和污染水平,为后续VOCs治理及在线监测体系的建设与优化提供可靠的数据支撑。